Forklift trucks have proven to be extremely useful in moving loads by means of inserting forks under the loads and raising the loads with the forks. Variations of the forklift-type structure for crane lifting are to be found in U.S. Pat. Nos. 3,897,097 and 3,971,478; British Pat. No. 791,430; and French Pat. No. 1.452.379. However, so far as applicant is aware, forklift-type lifting devices have not been widely applied in crane lifting and it is believed that one of the reasons for this is the fact that the prior art crane forklift devices have not adapted to lifting loads placed on non-level surfaces.
Additionally, U.S. Pat. Nos. 590,847; 2,847,245; 3,173,556; 3,193,887; 3,712,661 and 3,888,536 are mentioned as other forms of crane or hoist-type lift devices. U.S. Pat. No. 3,173,556, while not deemed of particular significance, does have a center telescoping member although structurally and functionally different from applicant's device.
Thus, the object of the invention becomes that of providing an improved forklift-type lifting apparatus for use with cranes, hoists, or the like.